Bluetooth technology allows Bluetooth devices to discover one another when they are within range and then to connect to one another. Discovery and subsequent connection to another Bluetooth device occurs through inquiry and page scan operations. The purpose of the inquiry operation is to discover other Bluetooth devices; and, the purpose of the page scan operation is to connect to other Bluetooth devices.
In operation, a first Bluetooth device, termed a “master”, acts as an inquirer by transmitting short packets at a very fast rate. A second device, termed a “slave”, listens for those packets by conducting an inquiry scan at a much slower rate. During this process, channel hopping is employed, as will be appreciated by the skilled artisan, so that eventually the devices will synchronize up with one another.
One of the problems associated with the discovery process is that during the time when the slave device listens for packets in its inquiry scan, the slave device is in a full receive state or mode, meaning that current draw and power consumption are high. This problem can be particularly challenging in the context of battery-powered devices.